Non steroidal, anti-inflammatory drugs (NSAIDS), such as aspirin and ibuprofen, are widely used for relieving pain and inflammation. Adverse side-effects, particularly in the kidneys, stomach, and intestines, are common with existing NSAIDS. MK-0966 is an investigational research drug which is being developped for the relief of pain and for the treatment of diseases such as arthritis. MK-0966 is being studied to see if it is as effective as existing NSAIDS and causes fewer side effects. The purpose of this research study is to investigate the effectiveness, tolerability and safety of MK-0966 12.5 mg and 25 mg daily in osteoarthritis patients aged 80 and older.